Maintenance: add revive linter

.golangci.yml

@@ -17,6 +17,9 @@ issues:
     - path: internal/configuration/
       linters:
         - dupl
+    - text: "exported: exported var Err*"
+      linters:
+        - revive
 linters:
   disable-all: true
   enable:
@@ -55,6 +58,7 @@ linters:
     - nolintlint
     - prealloc
     - predeclared
+    - revive
     - rowserrcheck
     - sqlclosecheck
     - staticcheck

internal/configuration/dnsblacklist.go

@@ -29,11 +29,7 @@ func (settings *DNS) readBlacklistBuilding(r reader) (err error) {
 		return err
 	}
 
-	if err := settings.readBlacklistUnblockedHostnames(r); err != nil {
-		return err
-	}
-
-	return nil
+	return settings.readBlacklistUnblockedHostnames(r)
 }
 
 var (

internal/configuration/firewall.go

@@ -69,11 +69,7 @@ func (settings *Firewall) read(r reader) (err error) {
 		return err
 	}
 
-	if err := settings.readOutboundSubnets(r); err != nil {
-		return err
-	}
-
-	return nil
+	return settings.readOutboundSubnets(r)
 }
 
 func (settings *Firewall) readVPNInputPorts(env params.Env) (err error) {

internal/configuration/settings.go

@@ -1,6 +1,8 @@
 package configuration
 
 import (
+	"errors"
+	"fmt"
 	"strings"
 
 	"github.com/qdm12/golibs/logging"
@@ -43,6 +45,18 @@ func (settings *Settings) lines() (lines []string) {
 	return lines
 }
 
+var (
+	ErrOpenvpn       = errors.New("cannot read Openvpn settings")
+	ErrSystem        = errors.New("cannot read System settings")
+	ErrDNS           = errors.New("cannot read DNS settings")
+	ErrFirewall      = errors.New("cannot read firewall settings")
+	ErrHTTPProxy     = errors.New("cannot read HTTP proxy settings")
+	ErrShadowsocks   = errors.New("cannot read Shadowsocks settings")
+	ErrControlServer = errors.New("cannot read control server settings")
+	ErrUpdater       = errors.New("cannot read Updater settings")
+	ErrPublicIP      = errors.New("cannot read Public IP getter settings")
+)
+
 // Read obtains all configuration options for the program and returns an error as soon
 // as an error is encountered reading them.
 func (settings *Settings) Read(env params.Env, os os.OS, logger logging.Logger) (err error) {
@@ -54,35 +68,35 @@ func (settings *Settings) Read(env params.Env, os os.OS, logger logging.Logger)
 	}
 
 	if err := settings.OpenVPN.read(r); err != nil {
-		return err
+		return fmt.Errorf("%w: %s", ErrOpenvpn, err)
 	}
 
 	if err := settings.System.read(r); err != nil {
-		return err
+		return fmt.Errorf("%w: %s", ErrSystem, err)
 	}
 
 	if err := settings.DNS.read(r); err != nil {
-		return err
+		return fmt.Errorf("%w: %s", ErrDNS, err)
 	}
 
 	if err := settings.Firewall.read(r); err != nil {
-		return err
+		return fmt.Errorf("%w: %s", ErrFirewall, err)
 	}
 
 	if err := settings.HTTPProxy.read(r); err != nil {
-		return err
+		return fmt.Errorf("%w: %s", ErrHTTPProxy, err)
 	}
 
 	if err := settings.ShadowSocks.read(r); err != nil {
-		return err
+		return fmt.Errorf("%w: %s", ErrShadowsocks, err)
 	}
 
 	if err := settings.ControlServer.read(r); err != nil {
-		return err
+		return fmt.Errorf("%w: %s", ErrControlServer, err)
 	}
 
 	if err := settings.Updater.read(r); err != nil {
-		return err
+		return fmt.Errorf("%w: %s", ErrUpdater, err)
 	}
 
 	if ip := settings.DNS.PlaintextAddress; ip != nil {
@@ -90,7 +104,7 @@ func (settings *Settings) Read(env params.Env, os os.OS, logger logging.Logger)
 	}
 
 	if err := settings.PublicIP.read(r); err != nil {
-		return err
+		return fmt.Errorf("%w: %s", ErrPublicIP, err)
 	}
 
 	return nil

internal/constants/addresses.go

@@ -1,5 +1,6 @@
 package constants
 
 const (
+	// HealthcheckAddress is the default listening address for the healthcheck server.
 	HealthcheckAddress = "127.0.0.1:9999"
 )

internal/constants/openvpn.go

@@ -1,3 +1,4 @@
+//nolint:revive
 package constants
 
 const (

internal/constants/paths.go

@@ -21,10 +21,10 @@ const (
 	RootHints string = "/etc/unbound/root.hints"
 	// RootKey is the filepath to the root.key file used by Unbound.
 	RootKey string = "/etc/unbound/root.key"
-	// Client key filepath, used by Cyberghost.
+	// ClientKey is the client key filepath.
 	ClientKey string = "/gluetun/client.key"
-	// Client certificate filepath, used by Cyberghost.
+	// ClientCertificate is the client certificate filepath.
 	ClientCertificate string = "/gluetun/client.crt"
-	// Servers information filepath.
+	// ServersData is the server information filepath.
 	ServersData = "/gluetun/servers.json"
 )

internal/constants/privado.go

@@ -48,6 +48,7 @@ func PrivadoHostnameChoices() (choices []string) {
 }
 
 //nolint:lll
+// PrivadoServers returns a slice of all the Privado servers.
 func PrivadoServers() []models.PrivadoServer {
 	return []models.PrivadoServer{
 		{Country: "Argentina", Region: "Buenos Aires F.D.", City: "Buenos Aires", Hostname: "eze-001.vpn.privado.io", IP: net.IP{168, 205, 93, 211}},

internal/constants/status.go

@@ -1,3 +1,4 @@
+//nolint:revive
 package constants
 
 import (

internal/constants/vpn.go

@@ -11,7 +11,7 @@ const (
 	Ivpn = "ivpn"
 	// Mullvad is a VPN provider.
 	Mullvad = "mullvad"
-	// NordVPN is a VPN provider.
+	// Nordvpn is a VPN provider.
 	Nordvpn = "nordvpn"
 	// Privado is a VPN provider.
 	Privado = "privado"
@@ -21,7 +21,7 @@ const (
 	Privatevpn = "privatevpn"
 	// Protonvpn is a VPN provider.
 	Protonvpn = "protonvpn"
-	// PureVPN is a VPN provider.
+	// Purevpn is a VPN provider.
 	Purevpn = "purevpn"
 	// Surfshark is a VPN provider.
 	Surfshark = "surfshark"

internal/constants/vyprvpn.go

@@ -21,6 +21,7 @@ func VyprvpnRegionChoices() (choices []string) {
 }
 
 //nolint:lll
+// VyprvpnServers returns a slice of all the VyprVPN servers.
 func VyprvpnServers() []models.VyprvpnServer {
 	return []models.VyprvpnServer{
 		{Region: "Algeria", Hostname: "dz1.vyprvpn.com", TCP: false, UDP: true, IPs: []net.IP{{209, 99, 75, 20}}},

internal/constants/windscribe.go

@@ -40,6 +40,7 @@ func WindscribeHostnameChoices() (choices []string) {
 }
 
 //nolint:lll
+// WindscribeServers returns a slice of all the Windscribe servers.
 func WindscribeServers() []models.WindscribeServer {
 	return []models.WindscribeServer{
 		{Region: "Albania", City: "Tirana", Hostname: "al-002.whiskergalaxy.com", IPs: []net.IP{{31, 171, 152, 178}, {31, 171, 152, 179}, {31, 171, 152, 180}}},

internal/openvpn/loop.go

@@ -327,8 +327,5 @@ func writeOpenvpnConf(lines []string, openFile os.OpenFileFunc) error {
 	if err != nil {
 		return err
 	}
-	if err := file.Close(); err != nil {
-		return err
-	}
-	return nil
+	return file.Close()
 }

internal/provider/privateinternetaccess/portforward.go

@@ -25,6 +25,7 @@ var (
 	ErrBindPort = errors.New("cannot bind port")
 )
 
+// PortForward obtains a VPN server side port forwarded from PIA.
 //nolint:gocognit
 func (p *PIA) PortForward(ctx context.Context, client *http.Client,
 	openFile os.OpenFileFunc, logger logging.Logger, gateway net.IP, fw firewall.Configurator,

internal/routing/outboundsubnets.go

@@ -31,11 +31,7 @@ func (r *routing) setOutboundRoutes(outboundSubnets []net.IPNet,
 	}
 
 	r.removeOutboundSubnets(subnetsToRemove, defaultInterfaceName, defaultGateway)
-	if err := r.addOutboundSubnets(subnetsToAdd, defaultInterfaceName, defaultGateway); err != nil {
-		return err
-	}
-
-	return nil
+	return r.addOutboundSubnets(subnetsToAdd, defaultInterfaceName, defaultGateway)
 }
 
 func (r *routing) removeOutboundSubnets(subnets []net.IPNet,

internal/unix/constants.go

@@ -5,5 +5,5 @@ import sysunix "golang.org/x/sys/unix"
 // Constants used for convenience so "os" does not have to be imported
 
 const (
-	S_IFCHR = sysunix.S_IFCHR //nolint:golint
+	S_IFCHR = sysunix.S_IFCHR //nolint:revive
 )